Advanced Materials Research Vols. 750-752

Abstract: The short carbon fibers/ room temperature vulcanizing silicone rubber composites were prepared by mechanical mixing method and vulcanization at room temperature for 7 days as internal insulator. The effects of the content of fiber on the mechanical , ablative and adhesive performances for the composites were investigated. The results show that with increasing content of carbon fiber filled, the tensile strength increases, the break elongation decreases, and the ablation rate (Rt) of the composites decreases rapidly at first, then increases. When carbon fiber content is 10phr, the ablation rate (Rt) is 0.076mm/s. no significant differences in adhesive values were obtained yet.

Abstract: In this paper, a new kind of clay copolymer adsorbent, bentonite compositing with maleic anhydride (MAH)-acrylic acid (AA)-vinyl acetate (VAc) copolymer (NaB/PMAV) was prepared by in-situ polymerization. It was used as polymer adsorbent for removing Pb (II) ions in wastewater.. Under the optimal condition of adsorption, the removal rate reached to 94.4% and the adsorption capacity got to 235.9 mg/g. Adsorption dynamics were consistent with pseudo-second-order kinetic model and isotherm model can meet the Langmuir isotherm.

Abstract: Chinese existing insulation materials mainly included inorganic thermal insulation materials and organic insulation materials, but short of composite insulation materials. This paper elaborated the research achievement and superiority of the composite insulation materials.

Abstract: Flexible conductive fibers were fabricated by in-situ chemical polymerization of pyrrole monomers on the surface of polyurethane (PU) fibers. Compact polypyrrole (PPy) surface layer were observed, and moreover, high structural stability of the composite fibers can be obtained due to interpenetrating interface formation and strong interaction between PPy layers and PU matrix. More importantly, the composite fibers exhibited high sensitivity with relative fast response and recovery time, and good reproducibility for chloroform vapor detection.

Abstract: According to the structure and mechanical characteristics, a CFRP (carbon fiber reinforced plastic) periscope outer tube was designed. The parameters were determined such as fiber orientation angles, number of layers, proportion of fiber with different angles, and stacking sequences. A finite element model was built for the analysis of bending strength and modal. A CFRP periscope outer tube specimen was processed for the bending performance test. The results of simulation and experiments show that the CFRP periscope outer tube could meet the requirements.

Abstract: Laminate floor coverings, with fiberboard in the middle layer, are hygroscopic which caused potential dimension instability. The paper tested thickness swelling (TS) and water absorption (WA) of 10 commercial laminate floors (LF) according to G/T 18102-2007 (GB/T) and LY/T 1611-2011(LY/T) and analyzed correlation between them. The results show that TS obtained by the GB/T method differed significantly from LY/T methods at the initial 14 days. 7d-TS and 7d-WA values of test specimen measuring 50 by 50mm both correlated well with internal bond (IB). For both kinds of test methods, the moisture content almost reached saturation at 28 days.

Abstract: Three-dimensional short carbon fiber felt reinforced C/SiC composites were prepared by the liquid silicon infiltration (LSI) process. The influences of different porosity ratios, carbon coating, and heat treatment of C/C substrates, on the properties of C/SiC composites were studied. The optimized porosity ratio is calculated as 40.1% when the volume percent of carbon fiber (including carbon coating) is 23%, and after screening porosity ratio from ~55% to ~20%, the optimized experimental result (39.5%) is highly in accordance with the design value. The C/SiC composite after process parameter optimization, has a flexural strength and modulus of 125 MPa and 120 GPa, respectively. The C/SiC composite without carbon coating has a flexural strength of only 77 MPa, showing carbon coating plays a key role. The heat treatment of C/C substrate at 1600°C also improves the flexural strength of C/SiC composite for nearly 50%, and porosity rearrangement and interface weakening are believed to contribute such improvement.

Abstract: For an copper-based composite friction material the accelerated testing effects was judged under three kinds of testing stress in this paper, that was, through the block design method and analysis, the forthright and functional judging method was given in certain extent for the accelerated testing designed by this paper. Meanwhile, the both methods about basic statistical analysis and basic accelerated life testing was used for discussing the statistical distribution laws on the experiment data which that the copper-based composite friction material were under three kinds of testing stress.

Abstract: Zirconyl chloride was used as zirconium source and fused silica particles were used as main raw material. First of all, the composite powders were prepared by wet chemical synthesis using ammonia as the precipitator and polyethylene glycol as the dispersant. Then, fused silica nanozirconia composite ceramic containing nanometer particle zirconia with different contents (5%, 15%, 25% and 35%) were fabricated in reduction atmosphere at 1300°C, 1350°C and 1400°C for 1 h. The bulk density and bending strength were measured, microstructure was observed by SEM. The result indicated bulk density and bending strength of composite ceramic increase and microstructure becomes denser with content of zirconia increasing. Bulk density of composite ceramic increases and bending strength which reaches maximum at 1350°C firstly increases then decreases with the increase of sintering temperature. Both high sintering temperature and nanozirconia possessing high energy interface can improve the composite ceramic sintering.

Abstract: The effects of brominated flame retardant which composed of decabromodiphenyl ethane (DBDPE) and antimonous oxide (AO) on long glass fiber reinforced polypropylene (LGFPP) were investigated by means of limiting oxygen index (LOI), vertical burning (UL-94), thermogravimetry analysis (TGA), and mechanical properties. With the increase of DBDPE-AO content, the LOI values of DBDPE-AO/LGFPP composites increased from 21 to 27.6, and when the content of DBDPE-AO was 16wt%, the composites passed the V-0 rating in UL-94 testing. The experimental results showed that the brominated flame retardant improved flame retardancy of LGFPP, which was proved by the TGA testing. Whats more, the mechanical properties of composites even improved compared with pure LGFPP.